When the Polytechnic High School building was constructed on a hill in east Fort Worth in 1936, it quickly became a landmark for a proud community whose roots dated to the 19th century.The building's grand Georgian Revival-style architecture, with a soaring tower that could be seen for miles, would become a beacon for several generations of graduates who cherished their school's history, traditions and reputation for excellence.But time changed Poly -- the school and its surrounding community. The demographics shifted, from all-white to mostly black, then to its current makeup, predominantly Hispanic. With that transformation, many alumni lost touch with their alma mater.But the newer generation of students, faculty and administrators needed that support. With many students struggling academically, Poly faced possible closure after several years of unacceptably low performance on state standardized tests.While inside the school building they were making changes to improve academics and avoid closure -- achieving a state "acceptable" rating in 2009 -- alumni, area residents and civic leaders, fearing the loss of identity that shutting the place would cause, worked on renewing public support.An alumni association that had formed in 2001 refocused its attention on the school and started getting others more involved. Last year, for example, the group donated $5,000 toward the $6,400 cost of new JROTC Color Guard uniforms.Association members identified other needs and located more alumni who could help. Out of that grew a first-ever all-class reunion to celebrate the 100th anniversary of the first graduating class, from 1912.More than 2,300, including students from across the decades, even 100-year-old Dora Brauer, Class of 1929, attended the celebration Saturday. The crowd was multiethnic, too. It looked like Poly over the years.The event was more successful than the organizers imagined, co-chair Rita Vinson said. And she expects the reconnection of a cross-section of alumni will provide direct support for the principal and staff, as well as give Poly advocates help in dealing with the district's central administration.This is the type of community resource that is crucial for urban public schools, especially those with many transient or disadvantaged students.Affluent suburban schools know the benefits of parental, alumni and community support. Some Fort Worth schools have gained from well-organized, committed groups willing to fill in where public dollars run short.Since its founding, the Poly Alumni Association has put more than $66,000 into scholarships, athletic equipment, student-incentive programs and appreciation events for faculty and students.Paschal High's alumni organization landscaped the front of the school on Forest Park Boulevard, and boosters will end up paying the cost of putting artificial turf on the football field.The challenge for Fort Worth school district leadership is to build on these models and determine how their best elements can be replicated to address the needs of other schools whose support groups are less-active or even nonexistent.The district has an extensive Adopt-A-School program in which area businesses assist individual schools, with money, mentors and other efforts.As the Poly experience has shown, alumni can be energized in new and very important ways.Drawing graduates back could be difficult in neighborhoods that have changed dramatically, as some areas of Fort Worth have. But those are likely to be where the students and faculty need their predecessors most, if they're going to succeed like previous generations did.